JP4120490B2

JP4120490B2 - Surface-coated cermet cutting tool that exhibits excellent chipping resistance with a hard coating layer in heavy cutting

Info

Publication number: JP4120490B2
Application number: JP2003177405A
Authority: JP
Inventors: 夏樹一宮; 一樹泉; 智行益野
Original assignee: Mitsubishi Materials Corp
Current assignee: Mitsubishi Materials Corp
Priority date: 2003-06-23
Filing date: 2003-06-23
Publication date: 2008-07-16
Anticipated expiration: 2023-06-23
Also published as: JP2005007558A

Description

【０００１】
【発明の属する技術分野】
この発明は、硬質被覆層がすぐれた高温強度を有し、したがって特にＴｉ基合金やＮｉ基合金、さらにＣｏ基合金およびＡｌ基合金などの非鉄合金材料などの被削材の切削加工を、高い機械的衝撃を伴う高切り込みや高送りなどの重切削加工条件で行なった場合に、硬質被覆層が長期に亘ってすぐれた耐チッピング性を発揮する表面被覆サーメット製切削工具（以下、被覆サーメット工具という）に関するものである。
【０００２】
【従来の技術】
一般に、被覆サーメット工具には、各種の鉄鋼材料や非鉄合金材料などの被削材の旋削加工や平削り加工にバイトの先端部に着脱自在に取り付けて用いられるスローアウエイチップ、前記被削材の穴あけ切削加工などに用いられるドリルやミニチュアドリル、さらに前記被削材の面削加工や溝加工、肩加工などに用いられるソリッドタイプのエンドミルなどがあり、また前記スローアウエイチップを着脱自在に取り付けて前記ソリッドタイプのエンドミルと同様に切削加工を行うスローアウエイエンドミル工具などが知られている。
【０００３】
また、被覆サーメット工具として、炭化タングステン（以下、ＷＣで示す）基超硬合金または炭窒化チタン（以下、ＴｉＣＮで示す）基サーメットで構成されたサーメット基体の表面に、
（ａ）表面潤滑層として、０．２〜３μｍの平均層厚を有する炭素層、
（ｂ）耐摩耗硬質層として、１〜１５μｍの平均層厚を有し、かつ、
組成式：（Ｔｉ_1-XＡｌ_X）Ｎ（ただし、原子比で、Ｘは０．４０〜０．６５を示す）を満足するＴｉとＡｌの複合窒化物［以下、（Ｔｉ，Ａｌ）Ｎで示す］層、以上（ａ）および（ｂ）からなる硬質被覆層を物理蒸着してなる被覆サーメット工具が知られており、前記（Ｔｉ，Ａｌ）Ｎ層が、構成成分であるＴｉによる高温強度、同Ａｌによる高温硬さと耐熱性を具備することから、前記被覆サーメット工具を特にＴｉ基合金やＮｉ基合金、さらにＣｏ基合金およびＡｌ基合金などの非鉄合金材料などの被削材の連続切削や断続切削加工に用いた場合に、炭素層による表面潤滑効果と相俟って、すぐれた切削性能を発揮することも知られている（例えば特許文献１参照）。
【０００４】
さらに、上記の被覆サーメット工具が、例えば図２に概略説明図で示される物理蒸着装置の１種であるアークイオンプレーティング装置に上記のサーメット基体を装入し、前記装置内にはカソード電極（蒸発源）として所定組成を有するＴｉ−Ａｌ合金および炭素がそれぞれセットされ、まず、ヒータで装置内を、例えば５００℃の温度に加熱した状態で、アノード電極と前記Ｔｉ−Ａｌ合金のカソード電極との間に、例えば９５Ａの電流を流してアーク放電を発生させ、同時に装置内に反応ガスとして窒素ガスを導入して、例えば４Ｐａの反応雰囲気とし、一方上記サーメット基体には、例えば−１５０Ｖのバイアス電圧を印加した条件で、前記サーメット基体の表面に、硬質被覆層として上記（Ｔｉ，Ａｌ）Ｎ層からなる耐摩耗硬質層を蒸着し、ついでアノード電極と前記炭素のカソード電極との間に、例えば９５Ａの電流を流してアーク放電を発生させ、同時に装置内の反応雰囲気を窒素ガスからＡｒ（アルゴン）ガスに切り替えて、１Ｐａの反応雰囲気とし、かつ前記サーメット基体に印加する電圧を５０Ｖとする条件で前記耐摩耗硬質層の上に炭素層を表面潤滑層として形成することにより製造されることも知られている（例えば特許文献１参照）。
【０００５】
【特許文献１】
特開２００２−１１３６０４
【０００６】
【発明が解決しようとする課題】
近年の切削加工装置の高性能化はめざましく、一方で切削加工に対する省力化および省エネ化、さらに低コスト化の要求は強く、これに伴い、切削加工効率向上の面から、切削加工は高切り込みや高送りなどの重切削加工条件で行なわれる傾向にあるが、上記の従来被覆サーメット工具においては、これを通常の切削加工条件で用いた場合には問題はないが、これを高い機械的衝撃を伴う高切り込みや高送りなどの重切削加工条件で行なった場合には、特に硬質被覆層の高温強度不足が原因でチッピング（微少欠け）が発生し易くなり、比較的短時間で使用寿命に至るのが現状である。
【０００７】
【課題を解決するための手段】
そこで、本発明者等は、上述のような観点から、特に重切削加工ですぐれた耐チッピング性を発揮する被覆サーメット工具を開発すべく、上記の従来被覆サーメット工具を構成する硬質被覆層に着目し、研究を行った結果、
（Ａ）上記の図２に示されるアークイオンプレーティング装置を用いて形成された従来被覆サーメット工具の硬質被覆層を構成する（Ｔｉ，Ａｌ）Ｎからなる耐摩耗硬質層は、層厚全体に亘って均質な高温強度、および高温硬さと耐熱性を有するが、例えば図１（ａ）に概略平面図で、同（ｂ）に概略正面図で示される構造のアークイオンプレーティング装置（以下、ＡＩＰ装置と略記する）とスパッタリング装置（以下、ＳＰ装置と略記する）が共存の蒸着装置、すなわち装置中央部にサーメット基体装着用回転テーブルを設け、前記回転テーブルを挟んで、一方側に上記の従来（Ｔｉ，Ａｌ）Ｎ層の形成にカソード電極（蒸発源）として用いられたＴｉ−Ａｌ合金に相当する相対的にＡｌ含有量の高いＴｉ−Ａｌ合金、他方側に相対的にＡｌ含有量の低いＴｉ−Ａｌ合金をいずれもカソード電極（蒸発源）として対向配置し、さらに炭素源として例えば炭素粉末成形体も配置した蒸着装置を用い、この装置の前記回転テーブル上の中心軸から半径方向に所定距離離れた位置に外周部に沿って複数のサーメット基体をリング状に装着し、まず、この状態で装置内雰囲気を窒素雰囲気として前記回転テーブルを回転させると共に、蒸着形成される耐摩耗硬質層の層厚均一化を図る目的でサーメット基体自体も自転させながら、前記の回転テーブルの両側に対向配置したカソード電極（蒸発源）とアノード電極との間にアーク放電を発生させて、前記サーメット基体の表面に（Ｔｉ，Ａｌ）Ｎ層を形成すると、この結果の（Ｔｉ，Ａｌ）Ｎ層においては、回転テーブル上にリング状に配置された前記サーメット基体が上記の一方側の相対的にＡｌ含有量の高いＴｉ−Ａｌ合金のカソード電極（蒸発源）に最も接近した時点で層中にＡｌ最高含有点が形成され、また前記サーメット基体が上記の他方側の相対的にＡｌ含有量の低いＴｉ−Ａｌ合金のカソード電極に最も接近した時点で層中にＡｌ最低含有点が形成され、上記回転テーブルの回転によって層中には層厚方向にそって前記Ａｌ最高含有点とＡｌ最低含有点が所定間隔をもって交互に繰り返し現れると共に、前記Ａｌ最高含有点から前記Ａｌ最低含有点、前記Ａｌ最低含有点から前記Ａｌ最高含有点へＴｉおよびＡｌの含有割合がそれぞれ連続的に変化する成分濃度分布構造をもつようになること。
【０００８】
（Ｂ）上記（Ａ）の繰り返し連続変化成分濃度分布構造の（Ｔｉ，Ａｌ）Ｎ層において、例えば対向配置のカソード電極（蒸発源）のそれぞれの組成を調製すると共に、サーメット基体が装着されている回転テーブルの回転速度を制御して、
上記Ａｌ最高含有点が、組成式：（Ｔｉ_1-XＡｌ_X）Ｎ（ただし、原子比で、Ｘは０．４０〜０．６５を示す）、
上記Ａｌ最低含有点が、組成式：（Ｔｉ_1-YＡｌ_Y）Ｎ（ただし、原子比で、Ｙは０．０５〜０．３５を示す）、
をそれぞれ満足し、かつ隣り合う上記Ａｌ最高含有点とＡｌ最低含有点の厚さ方向の間隔を０．０１〜０．１μmとすると、
上記Ａｌ最高含有点部分では、上記の従来（Ｔｉ，Ａｌ）Ｎ層と同等のＡｌ含有量となることから、前記従来（Ｔｉ，Ａｌ）Ｎ層と同等の高温硬さと耐熱性を示し、一方上記Ａｌ最低含有点部分は、前記Ａｌ最高含有点部分に比して相対的にＡｌ含有量が低く、Ｔｉ含有量の高いものとなるので、一段と高い高温強度を具備するようになり、かつこれらＡｌ最高含有点とＡｌ最低含有点の間隔をきわめて小さくしたことから、層全体の特性として高温硬さと耐熱性を保持した状態で、一段とすぐれた高温強度を具備するようになること。
【０００９】
（Ｃ）さらに、上記（Ａ）および（Ｂ）の繰り返し連続変化成分濃度分布構造の（Ｔｉ，Ａｌ）Ｎ層を１〜１５μｍの平均層厚で耐摩耗硬質層として蒸着形成し、ついで、同じく図１の蒸着装置におけるＳＰ装置を用い、Ａｒガスの反応雰囲気中で、上記の炭素粉末成形体のスパッタリングを行い、前記（Ｔｉ，Ａｌ）Ｎ層に重ねて表面潤滑層として０．２〜３μｍの平均層厚で非晶質炭素（以下、非晶質Ｃで示す）層を蒸着形成すると、この結果の硬質被覆層は、これの耐摩耗硬質層を構成する（Ｔｉ，Ａｌ）Ｎ層が、上記の繰り返し連続変化成分濃度分布構造によって上記の従来（Ｔｉ，Ａｌ）Ｎ層に比して一段とすぐれた高温強度を有するようになり、したがって硬質被覆層がかかる（Ｔｉ，Ａｌ）Ｎ層と非晶質Ｃ層からなる被覆サーメット工具は、非晶質Ｃ層による表面潤滑性向上効果と相俟って、特にＴｉ基合金やＮｉ基合金、さらにＣｏ基合金およびＡｌ基合金などの非鉄合金材料などの被削材の高い機械的衝撃を伴う高切り込みや高送りなどの重切削加工に用いた場合にも、すぐれた耐チッピング性を長期に亘って発揮するようになること。
以上（Ａ）〜（Ｃ）に示される研究結果を得たのである。
【００１０】
この発明は、上記の研究結果に基づいてなされたものであって、ＡＩＰ装置とＳＰ装置を備え、装置中央部にサーメット基体装着用回転テーブルを設けた蒸着装置を用い、
（ａ）上記回転テーブルを挟んで、上記ＡＩＰ装置のカソード電極（蒸発源）を両側に対向配置し、一方側のカソード電極（蒸発源）としてＡｌ最高含有点形成用Ｔｉ−Ａｌ合金、他方側のカソード電極（蒸発源）としてＡｌ最低含有点形成用Ｔｉ−Ａｌ合金をそれぞれ配置し、前記回転テーブル上の中心軸から半径方向に所定距離離れた位置にテーブルの外周部に沿って複数の上記サーメット基体をリング状に装着し、この状態で蒸着装置内雰囲気を窒素雰囲気として前記回転テーブルを回転させると共に、前記サーメット基体自体も自転させながら、前記の両側のカソード電極（蒸発源）とアノード電極との間にアーク放電を発生させて、前記サーメット基体の表面に蒸着してなる、１〜１５μｍの平均層厚を有し、
層厚方向にそって、Ａｌ最高含有点とＡｌ最低含有点とが所定間隔をおいて交互に繰り返し存在し、かつ前記Ａｌ最高含有点から前記Ａｌ最低含有点、前記Ａｌ最低含有点から前記Ａｌ最高含有点へＴｉおよびＡｌの含有割合がそれぞれ連続的に変化する成分濃度分布構造を有し、
さらに、上記Ａｌ最高含有点が、組成式：（Ｔｉ_1- _ＸＡｌ_Ｘ）Ｎ（ただし、原子比で、Ｘは０．４０〜０．６５を示す）、
上記Ａｌ最低含有点が、組成式：（Ｔｉ_1- _ＹＡｌ_Ｙ）Ｎ（ただし、原子比で、Ｙは０．０５〜０．３５を示す）、
をそれぞれ満足し、かつ隣り合う上記Ａｌ最高含有点とＡｌ最低含有点の間隔が、０．０１〜０．１μmである、（Ｔｉ，Ａｌ）Ｎ層からなる耐摩耗硬質層、
（ｂ）蒸着装置内雰囲気をＡｒガス雰囲気として上記回転テーブルを回転させると共に、前記回転テーブル上に同じくリング状に装着した上記サーメット基体自体も自転させながら、前記回転テーブルに面して配置した上記ＳＰ装置のカソード電極（蒸発源）である炭素源とアノード電極との間でスパッタリングを行い、前記回転テーブル上の前記サーメット基体表面に蒸着形成した上記耐摩耗硬質層に重ねて蒸着してなる、０．２〜３μｍの平均層厚を有する非晶質Ｃ層からなる表面潤滑層、
以上（ａ）および（ｂ）からなる硬質被覆層を蒸着形成してなる、重切削加工で硬質被覆層がすぐれた耐チッピング性を発揮する被覆サーメット工具に特徴を有するものである。
【００１１】
つぎに、この発明の被覆サーメット工具において、これを構成する硬質被覆層の構成を上記の通りに限定した理由を説明する。
（ａ）耐摩耗硬質層におけるＡｌ最低含有点の組成
Ａｌ最低含有点の（Ｔｉ，Ａｌ）ＮにおけるＴｉ成分には高温強度を向上させ、一方同Ａｌ成分には、高温硬さと耐熱性を向上させる作用があるので、前記Ａｌ最低含有点では相対的にＡｌ含有量を低くして、切削加工に必要な高温硬さと耐熱性を確保し、かつＴｉ含有量を相対的に高くして、重切削加工でチッピングを発生させないすぐれた高温強度を具備するようにしたものであるが、Ａｌの割合を示すＹ値がＴｉとの合量に占める割合（原子比、以下同じ）で０．０５未満になると、相対的にＴｉの割合が多くなり過ぎて、相対的に高い高温硬さと耐熱性を有するＡｌ最高含有点が隣接して存在しても層自体の高温硬さと耐熱性の低下は避けられず、この結果摩耗が促進するようになり、一方Ａｌの割合を示すＹ値が同０．３５を越えると、相対的にＴｉの割合が少なくなり過ぎて、重切削加工に要求されるすぐれた高温強度を確保することができなくなり、チッピングなどが発生し易くなることから、Ｙ値を０．０５〜０．３５と定めた。
【００１２】
（ｂ）耐摩耗硬質層におけるＡｌ最高含有点の組成
上記の通りＡｌ最高含有点は、上記の従来（Ｔｉ，Ａｌ）Ｎ層と同等の組成、すなわち相対的にＡｌ含有割合が高く、一方Ｔｉ含有量が低く、これによって相対的に高い高温硬さと耐熱性を有するようになるが、反面高温強度の劣るものであるため、このＡｌ最高含有点の高温強度不足を補う目的で、相対的にＴｉ含有割合が高く、一方Ａｌ含有量が低く、これによって相対的に高い高温強度を有するようになるＡｌ最低含有点を厚さ方向に交互に介在させるものであり、したがってＡｌの割合を示すＸ値がＴｉ成分との合量に占める割合で０．４０未満では、所望の高温硬さと耐熱性を確保することができず、一方同Ｘ値が０．６５を越えると、Ｔｉに対するＡｌの割合が多くなり過ぎて、Ａｌ最高含有点の高温強度が不十分となり、チッピング発生の原因となることから、Ａｌ最高含有点でのＡｌの割合を示すＸ値を０．４０〜０．６５と定めた。
【００１３】
（ｃ）耐摩耗硬質層におけるＡｌ最低含有点とＡｌ最高含有点間の間隔
その間隔が０．０１μm未満ではそれぞれの点を上記の組成で明確に形成することが困難であり、この結果耐摩耗硬質層にすぐれた高温強度と、高温硬さおよび耐熱性を確保することができなくなり、またその間隔が０．１μmを越えるとそれぞれの点がもつ欠点、すなわちＡｌ最高含有点であれば高温強度不足、Ａｌ最低含有点であれば高温硬さおよび耐熱性不足が層内に局部的に現れ、これが原因で切刃にチッピングが発生し易くなったり、摩耗が促進されるようになることから、その間隔を０．０１〜０．１μmと定めた。
【００１４】
（ｄ）耐摩耗硬質層の平均層厚
その平均層厚が１μｍ未満では、耐摩耗硬質層のもつすぐれた耐摩耗性を長期に亘って発揮するには不十分であり、一方その平均層厚が１５μｍを越えると切刃部にチッピングが発生し易くなることから、その平均層厚を１〜１５μｍと定めた。
【００１５】
（ｅ）表面潤滑層の平均層厚
硬質被覆層は、上記の通り耐摩耗硬質層のもつすぐれた高温強度と、高温硬さおよび耐熱性、さらに表面潤滑層である非晶質Ｃ層のもつすぐれた潤滑性によって、高い機械的衝撃を伴なう重切削加工ですぐれた耐チッピング性を発揮するようになるものであるが、その平均層厚が０．２μｍ未満では、所望の潤滑性向上効果を長期に亘って確保することができず、一方その平均層厚が３μｍを越えると切刃部にチッピングが発生し易くなることから、その平均層厚を０．２〜３μｍと定めた。
【００１６】
【発明の実施の形態】
つぎに、この発明の被覆サーメット工具を実施例により具体的に説明する。
（実施例１）
原料粉末として、いずれも１〜３μｍの平均粒径を有するＷＣ粉末、ＴｉＣ粉末、ＺｒＣ粉末、ＶＣ粉末、ＴａＣ粉末、ＮｂＣ粉末、Ｃr₃Ｃ₂粉末、ＴｉＮ粉末、ＴａＮ粉末、およびＣｏ粉末を用意し、これら原料粉末を、表１に示される配合組成に配合し、ボールミルで７２時間湿式混合し、乾燥した後、１００ＭＰａの圧力で圧粉体にプレス成形し、この圧粉体を６Ｐａの真空中、温度：１４００℃に１時間保持の条件で焼結し、焼結後、切刃部分にＲ：０．０３のホーニング加工を施してＩＳＯ規格・ＣＮＭＧ１２０４０８のチップ形状をもったＷＣ基超硬合金製のサーメット基体Ａ−１〜Ａ−１０を形成した。
【００１７】
また、原料粉末として、いずれも０．５〜２μｍの平均粒径を有するＴｉＣＮ（重量比でＴｉＣ／ＴｉＮ＝５０／５０）粉末、Ｍｏ₂Ｃ粉末、ＺｒＣ粉末、ＮｂＣ粉末、ＴａＣ粉末、ＷＣ粉末、Ｃｏ粉末、およびＮｉ粉末を用意し、これら原料粉末を、表２に示される配合組成に配合し、ボールミルで２４時間湿式混合し、乾燥した後、１００ＭＰａの圧力で圧粉体にプレス成形し、この圧粉体を２ｋＰａの窒素雰囲気中、温度：１５００℃に１時間保持の条件で焼結し、焼結後、切刃部分にＲ：０．０３のホーニング加工を施してＩＳＯ規格・ＣＮＭＧ１２０４０８のチップ形状をもったＴｉＣＮ系サーメット製のサーメット基体Ｂ−１〜Ｂ−６を形成した。
また、表面潤滑層である非晶質Ｃ層形成用カソード電極（蒸発源）として、９９．９８質量％の高純度を有する平均粒径：１μｍの高純度炭素粉末を１００ＭＰａの圧力でプレス成形してなる炭素粉末成形体を用意した。
【００１８】
ついで、上記のサーメット基体Ａ−１〜Ａ−１０およびＢ−１〜Ｂ−６のそれぞれを、アセトン中で超音波洗浄し、乾燥した状態で、図１に示される蒸着装置内の回転テーブル上の中心軸から半径方向に所定距離離れた位置に外周部にそって装着し、硬質被覆層の耐摩耗硬質層形成に、一方側のカソード電極（蒸発源）として、種々の成分組成をもったＡｌ最高含有点形成用Ｔｉ−Ａｌ合金、他方側のカソード電極（蒸発源）として、種々の成分組成をもったＡｌ最低含有点形成用Ｔｉ−Ａｌ合金を前記回転テーブルを挟んで対向配置し、さらに同じくカソード電極として上記の表面潤滑層形成用炭素粉末成形体およびボンバード洗浄用金属Ｔｉも装着し、まず装置内を排気して０．５Ｐａ以下の真空に保持しながら、ヒーターで装置内を５００℃に加熱した後、前記回転テーブル上で自転しながら回転するサーメット基体に−１０００Ｖの直流バイアス電圧を印加し、かつカソード電極の前記金属Ｔｉとアノード電極との間に１００Ａの電流を流してアーク放電を発生させ、もってサーメット基体表面をＴｉボンバード洗浄し、ついで装置内に反応ガスとして窒素ガスを導入して２Ｐａの反応雰囲気とすると共に、前記回転テーブル上で自転しながら回転するサーメット基体に−１００Ｖの直流バイアス電圧を印加し、かつそれぞれのカソード電極(前記Ａｌ最高含有点形成用Ｔｉ−Ａｌ合金およびＡｌ最低含有点形成用Ｔｉ−Ａｌ合金)とアノード電極との間に１００Ａの電流を流してアーク放電を発生させ、もって前記サーメット基体の表面に、層厚方向に沿って表３，４に示される目標組成のＡｌ最高含有点とＡｌ最低含有点とが交互に同じく表３，４に示される目標間隔で繰り返し存在し、かつ前記Ａｌ最高含有点から前記Ａｌ最低含有点、前記Ａｌ最低含有点から前記Ａｌ最高含有点へＴｉおよびＡｌの含有割合が連続的に変化する成分濃度分布構造を有し、かつ同じく表３，４に示される目標層厚の（Ｔｉ，Ａｌ）Ｎ層を硬質被覆層の耐摩耗硬質層として蒸着形成し、ついで上記のＡｌ最高含有点形成用Ｔｉ−Ａｌ合金およびＡｌ最低含有点形成用Ｔｉ−Ａｌ合金のカソード電極とアノード電極との間のアーク放電を停止し、装置内に導入する反応ガスをＡｒガスに切り替えて、装置内を１Ｐａの反応雰囲気とすると共に、カソード電極である前記炭素粉末成形体とアノード電極との間で、スパッタ出力：４ｋＷ、周波数：４０ｋＨｚの条件でスパッタリングを行ない、同じく表３，４に示される目標層厚の非晶質Ｃ層を硬質被覆層の表面潤滑層として蒸着形成しすることにより、本発明被覆サーメット工具としての本発明表面被覆サーメット製スローアウエイチップ（以下、本発明被覆チップと云う）１〜１６をそれぞれ製造した。
【００１９】
また、比較の目的で、これらサーメット基体Ａ−１〜Ａ−１０およびＢ−１〜Ｂ−６を、アセトン中で超音波洗浄し、乾燥した状態で、それぞれ同じく図１に示される蒸着装置に装入し、カソード電極（蒸発源）として種々の成分組成をもったＴｉ−Ａｌ合金（一方側のみ）および上記の炭素粉末成形体を装着し、またボンバード洗浄用金属Ｔｉも装着し、まず、装置内を排気して０．５Ｐａ以下の真空に保持しながら、ヒーターで装置内を５００℃に加熱した後、前記サーメット基体に−１０００Ｖの直流バイアス電圧を印加し、かつカソード電極の前記金属Ｔｉとアノード電極との間に１００Ａの電流を流してアーク放電を発生させ、もってサーメット基体表面をＴｉボンバード洗浄し、ついで装置内に反応ガスとして窒素ガスを導入して２Ｐａの反応雰囲気とすると共に、前記サーメット基体に印加するバイアス電圧を−１００Ｖに下げて、前記Ｔｉ−Ａｌ合金のカソード電極とアノード電極との間にアーク放電を発生させ、もって前記サーメット基体Ａ−１〜Ａ−１０およびＢ−１〜Ｂ−６のそれぞれの表面に、表５に示される目標組成および目標層厚を有し、かつ層厚方向に沿って実質的に組成変化のない（Ｔｉ，Ａｌ）Ｎ層を硬質被覆層の耐摩耗硬質層として蒸着形成し、ついで前記Ｔｉ−Ａｌ合金のカソード電極とアノード電極との間のアーク放電を停止し、装置内に導入する反応ガスをＡｒガスに切り替えて、同じく装置内を１Ｐａの反応雰囲気とすると共に、カソード電極である前記炭素粉末成形体とアノード電極との間で、同じくスパッタ出力：４ｋＷ、周波数：４０ｋＨｚの条件でスパッタリングを行ない、前記（Ｔｉ，Ａｌ）Ｎ層に重ねて、同じく表５に示される目標層厚の非晶質Ｃ層を硬質被覆層の表面潤滑層として蒸着形成することにより、比較被覆サーメット工具としての比較表面被覆サーメット製スローアウエイチップ（以下、比較被覆チップと云う）１〜１６をそれぞれ製造した。
【００２０】
つぎに、上記の各種の被覆チップを、いずれも工具鋼製バイトの先端部に固定治具にてネジ止めした状態で、本発明被覆チップ１〜１６および比較被覆チップ１〜１６について、
被削材：純Ｔｉ丸棒、
切削速度：７０ｍ／ｍｉｎ．、
切り込み：３．０ｍｍ、
送り：０．１ｍｍ／ｒｅｖ．、
切削時間：２０分、
の条件での純Ｔｉの乾式連続高切り込み重切削加工試験（通常の切り込み量は１．０ｍｍ）、
被削材：ＪＩＳ・Ａ４０３２の長さ方向等間隔４本縦溝入り丸棒、
切削速度：２００ｍ／ｍｉｎ．、
切り込み：４．０ｍｍ、
送り：０．２ｍｍ／ｒｅｖ．、
切削時間：２０分、
の条件でのＡｌ合金の乾式断続高切り込み重切削加工試験（通常の切り込み量は２．０ｍｍ）、
被削材：質量％（以下同じ）で、Ｎｉ−１５．５％Ｃｒ−８％Ｆｅ−０．０８％Ｃの組成を有するＮｉ合金丸棒、
切削速度：５０ｍ／ｍｉｎ．、
切り込み：１．０ｍｍ、
送り：０．４ｍｍ／ｒｅｖ．、
切削時間：２０分、
の条件でのＮｉ合金の乾式連続高送り重切削加工試験（通常の送り量は０．１ｍｍ／ｒｅｖ．）を行い、いずれの切削加工試験でも切刃の逃げ面摩耗幅を測定した。この測定結果を表６に示した。
【００２１】
【表１】

【００２２】
【表２】

【００２３】
【表３】

【００２４】
【表４】

【００２５】
【表５】

【００２６】
【表６】

【００２７】
（実施例２）
原料粉末として、平均粒径：５．５μｍを有する中粗粒ＷＣ粉末、同０．８μｍの微粒ＷＣ粉末、同１．３μｍのＴａＣ粉末、同１．２μｍのＮｂＣ粉末、同１．２μｍのＺｒＣ粉末、同２．３μｍのＣｒ₃Ｃ₂粉末、同１．５μｍのＶＣ粉末、同１．０μｍの（Ｔｉ，Ｗ）Ｃ［質量比で、ＴｉＣ／ＷＣ＝５０／５０］粉末、および同１．８μｍのＣｏ粉末を用意し、これら原料粉末をそれぞれ表７に示される配合組成に配合し、さらにワックスを加えてアセトン中で２４時間ボールミル混合し、減圧乾燥した後、１００ＭＰａの圧力で所定形状の各種の圧粉体にプレス成形し、これらの圧粉体を、６Ｐａの真空雰囲気中、７℃／分の昇温速度で１３７０〜１４７０℃の範囲内の所定の温度に昇温し、この温度に１時間保持後、炉冷の条件で焼結して、直径が８ｍｍ、１３ｍｍ、および２６ｍｍの３種のサーメット基体形成用丸棒焼結体を形成し、さらに前記の３種の丸棒焼結体から、研削加工にて、表７に示される組合せで、切刃部の直径×長さがそれぞれ６ｍｍ×１３ｍｍ、１０ｍｍ×２２ｍｍ、および２０ｍｍ×４５ｍｍの寸法、並びにいずれもねじれ角３０度の４枚刃スクエア形状をもったＷＣ基超硬合金製のサーメット基体（エンドミル）Ｃ−１〜Ｃ−８をそれぞれ製造した。
【００２８】
ついで、これらのサーメット基体（エンドミル）Ｃ−１〜Ｃ−８の表面をアセトン中で超音波洗浄し、乾燥した状態で、同じく図１に示される蒸着装置に装入し、上記実施例１と同一の条件で、層厚方向に沿って表８に示される目標組成のＡｌ最高含有点とＡｌ最低含有点とが交互に同じく表８に示される目標間隔で繰り返し存在し、かつ前記Ａｌ最高含有点から前記Ａｌ最低含有点、前記Ａｌ最低含有点から前記Ａｌ最高含有点へＴｉおよびＡｌの含有割合がそれぞれ連続的に変化する成分濃度分布構造を有し、同じく表８に示される目標層厚の（Ｔｉ，Ａｌ）Ｎ層からなる耐摩耗硬質層と、同じく表８に示される目標層厚の非晶質Ｃ層からなる表面潤滑層で構成された硬質被覆層を蒸着形成することにより、本発明被覆サーメット工具としての本発明表面被覆サーメット製エンドミル（以下、本発明被覆エンドミルと云う）１〜８をそれぞれ製造した。
【００２９】
また、比較の目的で、上記のサーメット基体（エンドミル）Ｃ−１〜Ｃ−８の表面をアセトン中で超音波洗浄し、乾燥した状態で、同じく図１に示される蒸着装置に装入し、上記実施例１と同一の条件で、表９に示される目標組成および目標層厚を有し、かつ層厚方向に沿って実質的に組成変化のない（Ｔｉ，Ａｌ）Ｎ層からなる耐摩耗硬質層と、同じく表９に示される目標層厚の非晶質Ｃ層からなる表面潤滑層で構成された硬質被覆層を蒸着形成することにより、比較被覆サーメット工具としての比較表面被覆サーメット製エンドミル（以下、比較被覆エンドミルと云う）１〜８をそれぞれ製造した。
【００３０】
つぎに、上記本発明被覆エンドミル１〜８および比較被覆エンドミル１〜８のうち、本発明被覆エンドミル１〜３および比較被覆エンドミル１〜３については、
被削材−平面：１００ｍｍ×２５０ｍｍ、厚さ：５０ｍｍの寸法を有する純Ｃｏ板材、
切削速度：１００ｍ／ｍｉｎ．、
溝深さ（切り込み）：３ｍｍ、
テーブル送り：４２００ｍｍ／分、
の条件での純Ｃｏの乾式高送り溝切削加工試験（通常のテーブル送り量は２０００ｍｍ／分）、本発明被覆エンドミル４〜６および比較被覆エンドミル４〜６については、
被削材−平面：１００ｍｍ×２５０ｍｍ、厚さ：５０ｍｍの寸法、およびＴｉ−６％Ａｌ−４％Ｖの組成を有するＴｉ合金板材、
切削速度：８０ｍ／ｍｉｎ．、
溝深さ（切り込み）：１０ｍｍ、
テーブル送り：９６０ｍｍ／分、
の条件でのＴｉ合金の乾式高切り込み溝切削加工試験（通常の溝深さ量は５ｍｍ）、本発明被覆エンドミル７，８および比較被覆エンドミル７，８については、被削材−平面：１００ｍｍ×２５０ｍｍ、厚さ：５０ｍｍの寸法、およびＮｉ−１５．５％Ｃｒ−８％Ｆｅ−０．０８％Ｃの組成を有するＮｉ合金板材、
切削速度：１００ｍ／ｍｉｎ．、
溝深さ（切り込み）：１０ｍｍ、
テーブル送り：１２００ｍｍ／分、
の条件でのＮｉ合金の乾式高送り溝切削加工試験（通常のテーブル送り量は６００ｍｍ／分）をそれぞれ行い、いずれの溝切削加工試験でも切刃部の外周刃の逃げ面摩耗幅が使用寿命の目安とされる０．１ｍｍに至るまでの切削溝長を測定した。この測定結果を表８、９にそれぞれ示した。
【００３１】
【表７】

【００３２】
【表８】

【００３３】
【表９】

【００３４】
（実施例３）
上記の実施例２で製造した直径が８ｍｍ（サーメット基体Ｃ−１〜Ｃ−３形成用）、１３ｍｍ（サーメット基体Ｃ−４〜Ｃ−６形成用）、および２６ｍｍ（サーメット基体Ｃ−７、Ｃ−８形成用）の３種の丸棒焼結体を用い、この３種の丸棒焼結体から、研削加工にて、溝形成部の直径×長さがそれぞれ４ｍｍ×１３ｍｍ（サーメット基体Ｄ−１〜Ｄ−３）、８ｍｍ×２２ｍｍ（サーメット基体Ｄ−４〜Ｄ−６）、および１６ｍｍ×４５ｍｍ（サーメット基体Ｄ−７、Ｄ−８）の寸法、並びにいずれもねじれ角３０度の２枚刃形状をもったＷＣ基超硬合金製のサーメット基体（ドリル）Ｄ−１〜Ｄ−８をそれぞれ製造した。
【００３５】
ついで、これらのサーメット基体（ドリル）Ｄ−１〜Ｄ−８の切刃に、ホーニングを施し、アセトン中で超音波洗浄し、乾燥した状態で、同じく図１に示される蒸着装置に装入し、上記実施例１と同一の条件で、層厚方向に沿って表１０に示される目標組成のＡｌ最高含有点とＡｌ最低含有点とが交互に同じく表１０に示される目標間隔で繰り返し存在し、かつ前記Ａｌ最高含有点から前記Ａｌ最低含有点、前記Ａｌ最低含有点から前記Ａｌ最高含有点へＴｉおよびＡｌの含有割合がそれぞれ連続的に変化する成分濃度分布構造を有し、かつ同じく表１０に示される目標層厚の（Ｔｉ，Ａｌ）Ｎ層からなる耐摩耗硬質層と、同じく表１０に示される目標層厚の非晶質Ｃ層からなる表面潤滑層で構成された硬質被覆層を蒸着形成することにより、本発明被覆サーメット工具としての本発明表面被覆サーメット製ドリル（以下、本発明被覆ドリルと云う）１〜８をそれぞれ製造した。
【００３６】
また、比較の目的で、上記のサーメット基体（ドリル）Ｄ−１〜Ｄ−８の表面に、ホーニングを施し、アセトン中で超音波洗浄し、乾燥した状態で、同じく図１に示される蒸着装置に装入し、上記実施例１と同一の条件で、表１１に示される目標組成および目標層厚を有し、かつ層厚方向に沿って実質的に組成変化のない（Ｔｉ，Ａｌ）Ｎ層からなる耐摩耗硬質層と、同じく表１１に示される目標層厚の非晶質Ｃ層からなる表面潤滑層で構成された硬質被覆層を蒸着形成することにより、比較被覆サーメット工具としての比較表面被覆サーメット製ドリル（以下、比較被覆ドリルと云う）１〜８をそれぞれ製造した。
【００３７】
つぎに、上記本発明被覆ドリル１〜８および比較被覆ドリル１〜８のうち、本発明被覆ドリル１〜３および比較被覆ドリル１〜３については、
被削材−平面：１００ｍｍ×２５０、厚さ：５０ｍｍの寸法を有する純Ｎｉ板材、
切削速度：５０ｍ／ｍｉｎ．、
送り：０．５ｍｍ／ｒｅｖ、
穴深さ：２０ｍｍ、
の条件での純Ｎｉの湿式高送り穴あけ切削加工試験（通常の送りは０．２ｍｍ／ｒｅｖ）、本発明被覆ドリル４〜６および比較被覆ドリル４〜６については、
被削材−平面：１００ｍｍ×２５０ｍｍ、厚さ：５０ｍｍの寸法、およびＴｉ−５％Ａｌ−２．５％Ｓｎの組成を有するＴｉ合金板材、
切削速度：５０ｍ／ｍｉｎ．、
送り：０．４ｍｍ／ｒｅｖ、
穴深さ：３０ｍｍ、
の条件でのＴｉ合金の湿式高送り穴あけ切削加工試験（通常の送りは０．２ｍｍ／ｒｅｖ）、本発明被覆ドリル７，８および比較被覆ドリル７，８については、被削材−平面：１００ｍｍ×２５０ｍｍ、厚さ：５０ｍｍの寸法、およびＮｉ−４８％Ｃｒ−０．４％Ｔｉ−０．０５％Ｃの組成を有するＮｉ合金板材、
切削速度：５０ｍ／ｍｉｎ．、
送り：０．４ｍｍ／ｒｅｖ、
穴深さ：４０ｍｍ、
の条件でのＮｉ合金の湿式高送り穴あけ切削加工試験（通常の送りは０．２ｍｍ／ｒｅｖ）、をそれぞれ行い、いずれの湿式穴あけ切削加工試験（水溶性切削油使用）でも先端切刃面の逃げ面摩耗幅が０．３ｍｍに至るまでの穴あけ加工数を測定した。この測定結果を表１０、１１にそれぞれ示した。
【００３８】
【表１０】

【００３９】
【表１１】

【００４０】
この結果得られた本発明被覆サーメット工具としての本発明被覆チップ１〜１６、本発明被覆エンドミル１〜８、および本発明被覆ドリル１〜８の硬質被覆層を構成する耐摩耗硬質層におけるＡｌ最高含有点とＡｌ最低含有点の組成、並びに比較被覆サーメット工具としての比較被覆チップ１〜１６、比較被覆エンドミル１〜８、および比較被覆ドリル１〜８の硬質被覆層の耐摩耗硬質層について、厚さ方向に沿ってＴｉおよびＡｌの含有量をオージェ分光分析装置を用いて測定したところ、前記本発明被覆サーメット工具の耐摩耗硬質層を構成する（Ｔｉ，Ａｌ）Ｎ層では、Ａｌ最高含有点とＡｌ最低含有点とがそれぞれ目標値と実質的に同じ組成および間隔で交互に繰り返し存在し、かつ前記Ａｌ最高含有点から前記Ａｌ最低含有点、前記Ａｌ最低含有点から前記Ａｌ最高含有点へＴｉおよびＡｌの含有割合がそれぞれ連続的に変化する成分濃度分布構造を有することが確認され、一方前記比較被覆サーメット工具の耐摩耗硬質層を構成する（Ｔｉ，Ａｌ）Ｎ層では厚さ方向に沿って組成変化が見られなかったが、目標組成と実質的に同じ組成を示した。
また、上記の硬質被覆層の表面潤滑層および耐摩耗硬質層の平均層厚を走査型電子顕微鏡を用いて断面測定したところ、いずれも目標層厚と実質的に同じ値を示した。
【００４１】
【発明の効果】
表３〜１１に示される結果から、硬質被覆層の耐摩耗硬質層が、層厚方向にＡｌ最高含有点とＡｌ最低含有点とが交互に所定間隔をおいて繰り返し存在し、かつ前記Ａｌ最高含有点から前記Ａｌ最低含有点、前記Ａｌ最低含有点から前記Ａｌ最高含有点へＴｉおよびＡｌの含有割合がそれぞれ連続的に変化する成分濃度分布構造を有する（Ｔｉ，Ａｌ）Ｎ層からなる本発明被覆サーメット工具は、いずれもＴｉ基合金やＮｉ基合金、さらにＣｏ基合金およびＡｌ基合金などの非鉄合金材料などの被削材の切削加工を高い機械的衝撃を伴う高切り込みや高送りの重切削条件で行っても、前記硬質被覆層の耐摩耗硬質層がすぐれた高温強度を具備することから、切削時にすぐれた耐チッピング性を発揮するのに対して、硬質被覆層の耐摩耗硬質層が層厚方向に沿って実質的に組成変化のない（Ｔｉ，Ａｌ）Ｎ層からなる比較被覆サーメット工具においては、高い機械的衝撃を伴う前記非鉄合金材料からなる被削材の重切削加工では、前記耐摩耗硬質層の高温強度不足が原因で、切刃部にチッピングが発生し、比較的短時間で使用寿命に至ることが明らかである。
上述のように、この発明の被覆サーメット工具は、特にＴｉ基合金やＮｉ基合金、さらにＣｏ基合金およびＡｌ基合金などの非鉄合金材料などの被削材などの通常の切削条件では勿論のこと、切削加工を重切削条件で行なった場合にもすぐれた耐チッピング性を発揮し、長期に亘ってすぐれた切削性能を示すものであるから、切削加工装置の高性能化、並びに切削加工の省力化および省エネ化、さらに低コスト化に十分満足に対応できるものである。
【図面の簡単な説明】
【図１】被覆サーメット工具を構成する硬質被覆層を形成するのに用いた蒸着装置を示し、（ａ）は概略平面図、（ｂ）は概略正面図である。
【図２】通常のアークイオンプレーティング装置の概略説明図である。[0001]
BACKGROUND OF THE INVENTION
In the present invention, the hard coating layer has an excellent high-temperature strength, and therefore, the cutting of a work material such as a non-ferrous alloy material such as a Ti base alloy, a Ni base alloy, a Co base alloy, and an Al base alloy is particularly high. A surface-coated cermet cutting tool (hereinafter referred to as a coated cermet tool) whose hard coating layer exhibits excellent chipping resistance for a long period of time when subjected to heavy cutting processing conditions such as high cutting with mechanical impact and high feed. )).
[0002]
[Prior art]
In general, a coated cermet tool is a throwaway insert that is used by being attached to the tip of a cutting tool for turning or planing of various steel materials and non-ferrous alloy materials. There are drills and miniature drills used for drilling, etc., solid type end mills used for chamfering, grooving, shoulder processing etc. of the work material, etc. A slow-away end mill tool or the like that performs cutting work in the same manner as the solid type end mill is known.
[0003]
Further, as a coated cermet tool, on the surface of a cermet base composed of tungsten carbide (hereinafter referred to as WC) based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) based cermet,
(A) As a surface lubricating layer, a carbon layer having an average layer thickness of 0.2 to 3 μm,
(B) the wear-resistant hard layer has an average layer thickness of 1 to 15 μm, and
Composition formula: (Ti_1-XAl_X) Ti and Al composite nitride [hereinafter referred to as (Ti, Al) N] layer satisfying N (wherein X represents 0.40 to 0.65 in atomic ratio), (a) and A coated cermet tool obtained by physical vapor deposition of a hard coating layer made of (b) is known, and the (Ti, Al) N layer has high-temperature strength due to Ti as a constituent component, high-temperature hardness and heat resistance due to Al. In particular, when the coated cermet tool is used for continuous cutting or intermittent cutting of non-ferrous alloy materials such as Ti-based alloys, Ni-based alloys, and Co-based alloys and Al-based alloys. It is also known that, together with the surface lubrication effect by the carbon layer, it exhibits excellent cutting performance (see, for example, Patent Document 1).
[0004]
Furthermore, the above-mentioned coated cermet tool has the above-mentioned cermet substrate loaded in an arc ion plating apparatus which is one of physical vapor deposition apparatuses schematically shown in FIG. 2, for example, and a cathode electrode ( Ti-Al alloy and carbon having a predetermined composition are set as the evaporation source). First, an anode electrode and a cathode electrode of the Ti-Al alloy are heated with a heater, for example, at a temperature of 500 ° C. During this time, for example, a current of 95 A is passed to generate an arc discharge, and at the same time, nitrogen gas is introduced into the apparatus as a reaction gas to obtain a reaction atmosphere of, for example, 4 Pa, while the cermet substrate has a bias of, for example, −150 V A wear resistant hard layer composed of the above (Ti, Al) N layer as a hard coating layer on the surface of the cermet substrate under the condition of applying a voltage. Next, an electric current of 95 A, for example, is passed between the anode electrode and the carbon cathode electrode to generate an arc discharge, and at the same time, the reaction atmosphere in the apparatus is switched from nitrogen gas to Ar (argon) gas, and 1 Pa It is also known that it is produced by forming a carbon layer as a surface lubrication layer on the wear-resistant hard layer under the conditions of the above reaction atmosphere and a voltage applied to the cermet substrate of 50 V (for example, patents) Reference 1).
[0005]
[Patent Document 1]
JP 2002-113604 A
[0006]
[Problems to be solved by the invention]
In recent years, there has been a remarkable improvement in the performance of cutting devices. On the other hand, there is a strong demand for labor saving and energy saving and further cost reduction for cutting work. Although there is a tendency to be performed under heavy cutting conditions such as high feed, the conventional coated cermet tool has no problem when it is used under normal cutting conditions, but it has a high mechanical impact. When it is carried out under heavy cutting conditions such as high cutting and high feed, chipping (small chipping) is likely to occur, especially due to insufficient high-temperature strength of the hard coating layer, and the service life is reached in a relatively short time. is the current situation.
[0007]
[Means for Solving the Problems]
Therefore, the present inventors focus on the hard coating layer constituting the conventional coated cermet tool in order to develop a coated cermet tool exhibiting excellent chipping resistance particularly in heavy cutting from the above viewpoint. As a result of research,
(A) The wear resistant hard layer made of (Ti, Al) N constituting the hard coating layer of the conventional coated cermet tool formed using the arc ion plating apparatus shown in FIG. The arc ion plating apparatus (hereinafter referred to as the following), which has a uniform high temperature strength and high temperature hardness and heat resistance, for example, in a schematic plan view in FIG. 1A and a schematic front view in FIG. A vapor deposition apparatus in which an AIP apparatus is abbreviated and a sputtering apparatus (hereinafter abbreviated as an SP apparatus), that is, a rotating table for mounting a cermet substrate is provided in the center of the apparatus, A Ti-Al alloy having a relatively high Al content corresponding to the Ti-Al alloy conventionally used as a cathode electrode (evaporation source) for forming a (Ti, Al) N layer, relatively on the other side l Using a vapor deposition apparatus in which all Ti-Al alloys having a low content are arranged facing each other as a cathode electrode (evaporation source), and further, for example, a carbon powder compact is arranged as a carbon source, and the central axis on the rotary table of this apparatus A plurality of cermet bases are mounted in a ring shape along the outer peripheral portion at a predetermined distance in the radial direction from the first, and first, in this state, the atmosphere inside the apparatus is turned into a nitrogen atmosphere and the rotary table is rotated and vapor deposition is formed. Arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode facing each other on both sides of the rotary table while rotating the cermet substrate itself for the purpose of uniforming the thickness of the wear-resistant hard layer. When the (Ti, Al) N layer is formed on the surface of the cermet substrate, the resulting (Ti, Al) N layer is ring-shaped on the rotary table. When the placed cermet substrate is closest to the cathode electrode (evaporation source) of the Ti-Al alloy having a relatively high Al content on one side, the highest Al content point is formed in the layer. When the cermet substrate is closest to the cathode electrode of the Ti-Al alloy having a relatively low Al content on the other side, an Al minimum content point is formed in the layer. The Al highest content point and the Al lowest content point appear alternately at predetermined intervals along the layer thickness direction, and from the Al highest content point to the Al lowest content point, from the Al lowest content point to the Al highest content point. It has a component concentration distribution structure in which the content ratios of Ti and Al change continuously.
[0008]
(B) In the (Ti, Al) N layer having the repeated continuous change component concentration distribution structure of (A) above, for example, the respective compositions of the cathode electrodes (evaporation sources) arranged opposite to each other are prepared, and a cermet substrate is mounted. By controlling the rotation speed of the rotating table
The Al highest content point is the composition formula: (Ti_1-XAl_X) N (however, in atomic ratio, X represents 0.40 to 0.65),
The minimum Al content point is the composition formula: (Ti_1-YAl_Y) N (however, in atomic ratio, Y represents 0.05 to 0.35),
And the interval in the thickness direction between the adjacent Al highest content point and Al lowest content point adjacent to each other is 0.01 to 0.1 μm,
The Al highest content point portion has an Al content equivalent to that of the conventional (Ti, Al) N layer, and thus exhibits the same high temperature hardness and heat resistance as the conventional (Ti, Al) N layer. The Al minimum content point portion has a relatively low Al content and a high Ti content as compared with the Al maximum content point portion, so that it has a higher high-temperature strength, and these Since the interval between the highest Al content point and the lowest Al content point is made extremely small, it should have even better high temperature strength while maintaining high temperature hardness and heat resistance as the characteristics of the entire layer.
[0009]
(C) Further, the (Ti, Al) N layer having the repeated continuous change component concentration distribution structure of the above (A) and (B) is vapor-deposited as an abrasion-resistant hard layer with an average layer thickness of 1 to 15 μm. Sputtering of the above-mentioned carbon powder compact is performed in an Ar gas reaction atmosphere using the SP apparatus in the vapor deposition apparatus of FIG. 1, and 0.2 to 3 μm is formed as a surface lubrication layer on the (Ti, Al) N layer. When an amorphous carbon (hereinafter referred to as amorphous C) layer is formed by vapor deposition at an average layer thickness, the resulting hard coating layer is composed of the (Ti, Al) N layer constituting the wear-resistant hard layer. The above-described repeated continuous change component concentration distribution structure has a high temperature strength which is superior to the conventional (Ti, Al) N layer, and thus a hard coating layer is applied to the (Ti, Al) N layer. Coated cermet comprising an amorphous C layer In combination with the effect of improving surface lubricity by the amorphous C layer, the cutting tool is particularly suitable for work materials such as non-ferrous alloy materials such as Ti-base alloys, Ni-base alloys, Co-base alloys, and Al-base alloys. Even when used for heavy cutting such as high cutting and high feed with high mechanical impact, it should exhibit excellent chipping resistance over a long period of time.
The research results shown in (A) to (C) above were obtained.
[0010]
  This invention was made based on the above research results,A vapor deposition apparatus provided with an AIP apparatus and an SP apparatus and provided with a cermet substrate mounting rotary table in the center of the apparatus,
(A) A cathode electrode (evaporation source) of the AIP device is disposed on both sides across the rotary table, and the Ti-Al alloy for forming the highest Al content point as the cathode electrode (evaporation source) on one side, the other side Ti-Al alloy for forming the lowest Al content point is disposed as a cathode electrode (evaporation source) of each of the above, and a plurality of the above-mentioned components are arranged along the outer peripheral portion of the table at a predetermined distance in the radial direction from the central axis on the rotary table A cermet substrate is mounted in a ring shape, and in this state, the atmosphere inside the vapor deposition apparatus is set to a nitrogen atmosphere, the rotating table is rotated, and the cermet substrate itself is rotated, while the cathode electrodes (evaporation sources) and anode electrodes on both sides are rotated. And having an average layer thickness of 1 to 15 μm formed by vapor-depositing on the surface of the cermet substrate.,
  Along the layer thickness direction, the Al highest content point and the Al lowest content point are alternately present at predetermined intervals, and the Al highest content point to the Al lowest content point, the Al lowest content point to the Al It has a component concentration distribution structure in which the content ratios of Ti and Al continuously change to the highest content point,
  Furthermore, the Al highest content point is the composition formula: (Ti_1- _XAl_X) N (however, in atomic ratio, X represents 0.40 to 0.65),
  The minimum Al content point is the composition formula: (Ti_1- _YAl_Y) N (however, in atomic ratio, Y represents 0.05 to 0.35),
A wear resistant hard layer made of a (Ti, Al) N layer, wherein the distance between the Al highest content point and the Al lowest content point adjacent to each other is 0.01 to 0.1 μm,
(B)While rotating the rotary table with the atmosphere inside the vapor deposition apparatus as an Ar gas atmosphere, and rotating the cermet substrate itself mounted in a ring shape on the rotary table, the SP apparatus arranged facing the rotary table Sputtering is performed between a carbon source, which is a cathode electrode (evaporation source), and an anode electrode, and deposited on the wear-resistant hard layer deposited on the surface of the cermet substrate on the rotary table. Having an average layer thickness of ~ 3 μmA surface lubrication layer comprising an amorphous C layer;
The present invention is characterized by a coated cermet tool that is formed by vapor-depositing the hard coating layer comprising the above (a) and (b) and exhibits excellent chipping resistance in the heavy cutting process.
[0011]
Next, in the coated cermet tool of the present invention, the reason why the configuration of the hard coating layer constituting the tool is limited as described above will be described.
(A) Composition of Al minimum content point in wear-resistant hard layer
The Ti component in (Ti, Al) N at the lowest Al content point improves the high temperature strength, while the Al component has the effect of improving the high temperature hardness and heat resistance. In addition, the Al content is reduced to ensure the high temperature hardness and heat resistance necessary for cutting, and the Ti content is relatively increased to provide excellent high temperature strength that does not cause chipping in heavy cutting. However, when the Y value indicating the proportion of Al is less than 0.05 in terms of the total amount with Ti (atomic ratio, hereinafter the same), the proportion of Ti is relatively increased. However, even if the Al highest content point having relatively high high temperature hardness and heat resistance exists adjacent to each other, a decrease in high temperature hardness and heat resistance of the layer itself is inevitable, and as a result, wear is promoted. Y value indicating the proportion of Al exceeds 0.35 And, since the ratio of Ti becomes relatively small, it becomes impossible to ensure the excellent high-temperature strength required for heavy cutting, and chipping is likely to occur. It was set to 0.35.
[0012]
(B) Composition of Al highest content point in wear-resistant hard layer
As described above, the highest Al content point is the same composition as the conventional (Ti, Al) N layer, that is, the Al content ratio is relatively high, while the Ti content is low, and thereby the relatively high high temperature hardness. Although it has heat resistance, on the other hand, it is inferior in high-temperature strength. Therefore, in order to compensate for the lack of high-temperature strength at the highest Al content point, the Ti content is relatively high, while the Al content is low. Thus, the Al minimum content point that has a relatively high high-temperature strength is alternately interposed in the thickness direction, and accordingly, the X value indicating the proportion of Al in the total amount with the Ti component is 0. If it is less than 40, the desired high-temperature hardness and heat resistance cannot be ensured. On the other hand, if the X value exceeds 0.65, the ratio of Al to Ti increases so that the high-temperature strength at the highest Al content point is high. Insufficient Since the cause of ring generation, was defined as 0.40 to 0.65 the X value indicating the proportion of Al in the Al up containing point.
[0013]
(C) The distance between the lowest Al content point and the highest Al content point in the wear-resistant hard layer
If the distance is less than 0.01 μm, it is difficult to clearly form each point with the above composition, and as a result, it is possible to ensure excellent high temperature strength, high temperature hardness and heat resistance in the wear resistant hard layer. If the distance exceeds 0.1 μm, the defects of each point, that is, if the highest Al content point is insufficient high temperature strength, if the lowest Al content point, high temperature hardness and insufficient heat resistance are present in the layer. Since it appears locally and chipping is likely to occur on the cutting edge due to this, or wear is promoted, the interval is set to 0.01 to 0.1 μm.
[0014]
(D) Average layer thickness of the wear-resistant hard layer
If the average layer thickness is less than 1 μm, it is insufficient to exhibit the excellent wear resistance of the wear-resistant hard layer over a long period. On the other hand, if the average layer thickness exceeds 15 μm, chipping occurs at the cutting edge. Since it becomes easy to generate | occur | produce, the average layer thickness was defined as 1-15 micrometers.
[0015]
(E) Average thickness of the surface lubricating layer
As described above, the hard coating layer has a high mechanical impact due to the excellent high temperature strength of the wear resistant hard layer, the high temperature hardness and heat resistance, and the excellent lubricity of the amorphous C layer as the surface lubricating layer. However, when the average layer thickness is less than 0.2 μm, it is possible to ensure the desired lubricity improvement effect over a long period of time. On the other hand, if the average layer thickness exceeds 3 μm, chipping is likely to occur at the cutting edge, so the average layer thickness was determined to be 0.2 to 3 μm.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, the coated cermet tool of the present invention will be specifically described with reference to examples.
Example 1
As raw material powders, WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, Cr, all having an average particle diameter of 1 to 3 μm._ThreeC₂Powder, TiN powder, TaN powder, and Co powder are prepared. These raw material powders are blended in the blending composition shown in Table 1, wet-mixed by a ball mill for 72 hours, dried, and then compacted at a pressure of 100 MPa. The green compact was sintered in a vacuum of 6 Pa at a temperature of 1400 ° C. for 1 hour. After sintering, the cutting edge portion was subjected to a honing process of R: 0.03 and ISO Cermet substrates A-1 to A-10 made of a WC-base cemented carbide having a standard / CNMG120408 chip shape were formed.
[0017]
In addition, as raw material powder, TiCN (TiC / TiN = 50/50 by weight) powder having an average particle diameter of 0.5 to 2 μm, Mo₂C powder, ZrC powder, NbC powder, TaC powder, WC powder, Co powder, and Ni powder are prepared. These raw material powders are blended in the blending composition shown in Table 2, and are wet-mixed for 24 hours in a ball mill and dried. After that, the green compact was press-molded into a green compact at a pressure of 100 MPa, and this green compact was sintered in a nitrogen atmosphere of 2 kPa at a temperature of 1500 ° C. for 1 hour. : A honing process of 0.03 was performed to form cermet bases B-1 to B-6 made of TiCN cermet having a chip shape of ISO standard / CNMG120408.
Also, as a cathode electrode (evaporation source) for forming an amorphous C layer, which is a surface lubricating layer, high purity carbon powder having a high purity of 99.98% by mass and an average particle diameter of 1 μm was pressed at a pressure of 100 MPa. A carbon powder molded body was prepared.
[0018]
Next, each of the cermet substrates A-1 to A-10 and B-1 to B-6 is ultrasonically cleaned in acetone and dried, and then on the rotary table in the vapor deposition apparatus shown in FIG. Attached along the outer peripheral portion at a predetermined distance in the radial direction from the central axis of the core, and with various component compositions as a cathode electrode (evaporation source) on one side for forming a hard-wearing hard layer of the hard coating layer Ti-Al alloy for forming the highest Al content point, and as the cathode electrode (evaporation source) on the other side, the Ti-Al alloy for forming the lowest Al content point having various component compositions is disposed opposite to the rotary table, Further, the carbon powder compact for forming the surface lubrication layer and the metal Ti for bombard cleaning are also mounted as the cathode electrode, and the inside of the apparatus is first evacuated and kept at a vacuum of 0.5 Pa or less while the inside of the apparatus is kept at 5 with a heater. After heating to 0 ° C., a DC bias voltage of −1000 V is applied to the cermet substrate that rotates while rotating on the rotary table, and a current of 100 A is passed between the metal Ti of the cathode electrode and the anode electrode. Arc discharge is generated, and the surface of the cermet substrate is cleaned with Ti bombardment. Then, nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of 2 Pa, and the cermet substrate that rotates while rotating on the rotary table A DC bias voltage of −100 V was applied, and a current of 100 A was applied between each cathode electrode (the Ti-Al alloy for forming the highest Al content point and the Ti—Al alloy for forming the lowest Al content point) and the anode electrode. As shown in Tables 3 and 4 along the layer thickness direction on the surface of the cermet substrate. The highest Al content point and the lowest Al content point of the target composition are alternately present at the target intervals shown in Tables 3 and 4 alternately, and from the highest Al content point to the lowest Al content point, the lowest Al content point Has a component concentration distribution structure in which the content ratio of Ti and Al continuously changes from the highest Al content point to the above-mentioned Al content point, and (Ti, Al) N layer having the target layer thickness shown in Tables 3 and 4 is hard-coated Then, the arc discharge between the cathode electrode and the anode electrode of the above-described Ti-Al alloy for forming the highest Al content point and Ti-Al alloy for forming the lowest Al content point is stopped. The reaction gas introduced into the apparatus is switched to Ar gas so that the inside of the apparatus has a reaction atmosphere of 1 Pa, and the sputter output is 4 k between the carbon powder compact that is the cathode electrode and the anode electrode: As a coated cermet tool of the present invention, sputtering is performed under the condition of frequency: 40 kHz, and an amorphous C layer having a target layer thickness shown in Tables 3 and 4 is deposited as a surface lubricating layer of the hard coating layer. The surface-coated cermet throwaway tips (hereinafter referred to as the present invention-coated tips) 1 to 16 of the present invention were produced.
[0019]
For comparison purposes, these cermet substrates A-1 to A-10 and B-1 to B-6 were ultrasonically cleaned in acetone and dried, respectively, in the vapor deposition apparatus shown in FIG. The Ti-Al alloy (only one side) having various component compositions as the cathode electrode (evaporation source) and the carbon powder molded body described above were mounted, and the bombard cleaning metal Ti was also mounted. While the inside of the apparatus was evacuated and kept at a vacuum of 0.5 Pa or less, the inside of the apparatus was heated to 500 ° C. with a heater, a DC bias voltage of −1000 V was applied to the cermet substrate, and the metal Ti of the cathode electrode A current of 100 A is passed between the anode electrode and the anode electrode to generate an arc discharge, thereby cleaning the surface of the cermet substrate with Ti bombardment, and then introducing nitrogen gas as a reaction gas into the apparatus. In addition to a reaction atmosphere of 2 Pa, the bias voltage applied to the cermet substrate is lowered to −100 V to generate an arc discharge between the cathode electrode and the anode electrode of the Ti—Al alloy, whereby the cermet substrate A— 1 to A-10 and B-1 to B-6 have the target composition and target layer thickness shown in Table 5, and substantially no composition change along the layer thickness direction (Ti , Al) N layer is vapor-deposited as an abrasion-resistant hard layer of the hard coating layer, then the arc discharge between the cathode electrode and the anode electrode of the Ti-Al alloy is stopped, and the reaction gas introduced into the apparatus is Ar. The gas is switched to a gas, and the inside of the apparatus is set to a reaction atmosphere of 1 Pa. Also, the sputter output: 4 kW, frequency between the carbon powder compact as the cathode electrode and the anode electrode. : Sputtering is performed at a condition of 40 kHz, and an amorphous C layer having a target layer thickness shown in Table 5 is deposited on the (Ti, Al) N layer as a surface lubricating layer of the hard coating layer. Comparative surface-coated cermet throwaway tips (hereinafter referred to as comparative coated tips) 1 to 16 as comparative coated cermet tools were produced, respectively.
[0020]
Next, in the state where each of the above various coated chips is screwed to the tip of the tool steel tool with a fixing jig, the present coated chips 1-16 and the comparative coated chips 1-16,
Work material: Pure Ti round bar,
Cutting speed: 70 m / min. ,
Cutting depth: 3.0 mm,
Feed: 0.1 mm / rev. ,
Cutting time: 20 minutes,
Pure Ti dry continuous high cutting heavy cutting test (normal cutting amount is 1.0 mm),
Work material: JIS A4032 lengthwise equidistant four round grooved round bars,
Cutting speed: 200 m / min. ,
Cutting depth: 4.0 mm,
Feed: 0.2 mm / rev. ,
Cutting time: 20 minutes,
Al-alloy dry interrupted high cutting heavy cutting test (normal cutting amount is 2.0 mm),
Work material: Ni alloy round bar having a composition of Ni-15.5% Cr-8% Fe-0.08% C in mass% (the same applies hereinafter),
Cutting speed: 50 m / min. ,
Cutting depth: 1.0 mm,
Feed: 0.4 mm / rev. ,
Cutting time: 20 minutes,
The dry continuous high feed heavy cutting test of Ni alloy under the conditions (normal feed amount is 0.1 mm / rev.) Was performed, and the flank wear width of the cutting edge was measured in any of the cutting tests. The measurement results are shown in Table 6.
[0021]
[Table 1]

[0022]
[Table 2]

[0023]
[Table 3]

[0024]
[Table 4]

[0025]
[Table 5]

[0026]
[Table 6]

[0027]
(Example 2)
As raw material powders, medium coarse WC powder having an average particle diameter of 5.5 μm, fine WC powder of 0.8 μm, TaC powder of 1.3 μm, NbC powder of 1.2 μm, ZrC of 1.2 μm Powder, 2.3 μm Cr_ThreeC₂Prepared powder, 1.5 μm VC powder, 1.0 μm (Ti, W) C [mass ratio, TiC / WC = 50/50] powder, and 1.8 μm Co powder. Each of the powders was blended into the composition shown in Table 7, further added with wax, ball mill mixed in acetone for 24 hours, dried under reduced pressure, and then pressed into various compacts of a predetermined shape at a pressure of 100 MPa, These green compacts were heated to a predetermined temperature in the range of 1370 to 1470 ° C. at a rate of temperature increase of 7 ° C./min in a vacuum atmosphere of 6 Pa, held at this temperature for 1 hour, and then subjected to furnace cooling conditions The three types of cermet substrate forming round bar sintered bodies having diameters of 8 mm, 13 mm, and 26 mm were formed, and further, the above three kinds of round bar sintered bodies were ground by grinding. In the combination shown in Fig. 7, the diameter x length of the cutting edge is Cermet substrates (end mills) C-1 to C- made of WC-base cemented carbide having a size of 6 mm × 13 mm, 10 mm × 22 mm, and 20 mm × 45 mm, and a four-blade square shape with a twist angle of 30 degrees. 8 were produced respectively.
[0028]
Then, the surfaces of these cermet substrates (end mills) C-1 to C-8 were ultrasonically cleaned in acetone and dried, and charged into the vapor deposition apparatus shown in FIG. Under the same conditions, the highest Al content point and the lowest Al content point of the target composition shown in Table 8 along the layer thickness direction are alternately repeated at the same target interval shown in Table 8, and the highest Al content The target layer thickness shown in Table 8 has a component concentration distribution structure in which the content ratios of Ti and Al continuously change from the point to the Al minimum content point and from the Al minimum content point to the Al maximum content point, respectively. By vapor-depositing a hard coating layer composed of a wear-resistant hard layer composed of (Ti, Al) N layer and a surface lubricating layer composed of an amorphous C layer having a target layer thickness also shown in Table 8, The coated cermet tool of the present invention and The present invention surface coating cermet end mill Te (hereinafter, the present invention refers to the coating end mill) 1-8 were prepared, respectively.
[0029]
For comparison purposes, the surfaces of the cermet substrates (end mills) C-1 to C-8 were ultrasonically cleaned in acetone and dried, and then charged into the vapor deposition apparatus shown in FIG. Wear resistance comprising a (Ti, Al) N layer having the target composition and target layer thickness shown in Table 9 and substantially unchanged in the layer thickness direction under the same conditions as in Example 1 above. A comparative surface-coated cermet end mill as a comparative coated cermet tool by vapor-depositing a hard coating layer composed of a hard layer and a surface lubricating layer composed of an amorphous C layer having a target layer thickness similarly shown in Table 9 1 to 8 (hereinafter referred to as comparative coated end mills) were produced.
[0030]
Next, of the present invention coated end mills 1-8 and comparative coated end mills 1-8, the present invention coated end mills 1-3 and comparative coated end mills 1-3 are as follows:
Work material—Plane: 100 mm × 250 mm, Thickness: 50 mm pure Co plate,
Cutting speed: 100 m / min. ,
Groove depth (cut): 3 mm,
Table feed: 4200 mm / min,
For the dry high feed groove cutting test of pure Co under the conditions of (normal table feed rate is 2000 mm / min), the present invention coated end mills 4-6 and comparative coated end mills 4-6,
Workpiece material-plane: 100 mm x 250 mm, thickness: 50 mm, Ti alloy plate material having a composition of Ti-6% Al-4% V,
Cutting speed: 80 m / min. ,
Groove depth (cut): 10 mm,
Table feed: 960 mm / min,
For the Ti alloy dry-type high-grooving groove cutting test (normal groove depth: 5 mm), the coated end mills 7 and 8 and the comparative coated end mills 7 and 8 of the present invention, the work material-plane: 100 mm × Ni alloy sheet having a dimension of 250 mm, thickness: 50 mm, and a composition of Ni-15.5% Cr-8% Fe-0.08% C,
Cutting speed: 100 m / min. ,
Groove depth (cut): 10 mm,
Table feed: 1200mm / min,
Ni alloy dry high feed groove cutting test under normal conditions (normal table feed rate is 600mm / min), and the flank wear width of the outer peripheral edge of the cutting edge in each groove cutting test is the service life The cutting groove length up to 0.1 mm, which is a guideline, was measured. The measurement results are shown in Tables 8 and 9, respectively.
[0031]
[Table 7]

[0032]
[Table 8]

[0033]
[Table 9]

[0034]
(Example 3)
The diameters produced in Example 2 above were 8 mm (for forming cermet substrates C-1 to C-3), 13 mm (for forming cermet substrates C-4 to C-6), and 26 mm (cermet substrates C-7 and C). -8 for forming), and from these three types of round bar sintered bodies, the diameter x length of the groove forming portion is 4 mm x 13 mm (cermet substrate D) by grinding. −1 to D-3), 8 mm × 22 mm (cermet bases D-4 to D-6), and 16 mm × 45 mm (cermet bases D-7 and D-8), and 2 with a twist angle of 30 degrees. Cermet substrates (drills) D-1 to D-8 made of a WC-base cemented carbide having a single blade shape were produced.
[0035]
Next, honing is applied to the cutting edges of these cermet substrates (drills) D-1 to D-8, ultrasonic cleaning is performed in acetone, and the dried blades are loaded into the vapor deposition apparatus shown in FIG. Under the same conditions as in Example 1 above, the Al highest content point and Al minimum content point of the target composition shown in Table 10 along the layer thickness direction are alternately repeated at the target interval shown in Table 10 as well. And having a component concentration distribution structure in which the content ratios of Ti and Al continuously change from the Al highest content point to the Al lowest content point, and from the Al lowest content point to the Al highest content point, respectively. A hard coating layer comprising a wear-resistant hard layer composed of a (Ti, Al) N layer having a target layer thickness shown in FIG. 10 and a surface lubricating layer composed of an amorphous C layer having a target layer thickness also shown in Table 10 By vapor deposition The present invention surface coating cermet drill as the present invention coated cermet tool (hereinafter, the present invention refers to the coating drills) 1-8 were prepared, respectively.
[0036]
Further, for the purpose of comparison, the surface of the cermet bases (drills) D-1 to D-8 is subjected to honing, ultrasonically cleaned in acetone, and dried, similarly to the vapor deposition apparatus shown in FIG. (Ti, Al) N having the target composition and target layer thickness shown in Table 11 and substantially no composition change along the layer thickness direction under the same conditions as in Example 1 above. Comparison as a comparative coated cermet tool by vapor-depositing a hard coating layer composed of a wear-resistant hard layer composed of layers and a surface lubricating layer composed of an amorphous C layer having a target layer thickness similarly shown in Table 11 Surface-coated cermet drills (hereinafter referred to as comparative coated drills) 1 to 8 were produced.
[0037]
Next, of the present invention coated drills 1-8 and comparative coated drills 1-8, for the present invention coated drills 1-3 and comparative coated drills 1-3,
Work material—Plane: 100 mm × 250, thickness: pure Ni plate material having dimensions of 50 mm,
Cutting speed: 50 m / min. ,
Feed: 0.5mm / rev,
Hole depth: 20mm,
With respect to the pure Ni wet high feed drilling test (normal feed is 0.2 mm / rev), the present invention coated drills 4-6 and comparative coated drills 4-6,
Work material-plane: 100 mm x 250 mm, thickness: 50 mm, and Ti alloy sheet having a composition of Ti-5% Al-2.5% Sn,
Cutting speed: 50 m / min. ,
Feed: 0.4mm / rev,
Hole depth: 30mm,
For the wet high-feed drilling test of Ti alloy under the conditions of the above (normal feed is 0.2 mm / rev), the coated drills 7 and 8 of the present invention and the comparative coated drills 7 and 8, work material-plane: 100 mm X 250 mm, thickness: Ni alloy plate having a dimension of 50 mm and a composition of Ni-48% Cr-0.4% Ti-0.05% C,
Cutting speed: 50 m / min. ,
Feed: 0.4mm / rev,
Hole depth: 40mm,
The Ni alloy wet high-feed drilling test (normal feed is 0.2 mm / rev) was performed, and any of the wet drilling tests (using water-soluble cutting oil) The number of drilling processes until the flank wear width reached 0.3 mm was measured. The measurement results are shown in Tables 10 and 11, respectively.
[0038]
[Table 10]

[0039]
[Table 11]

[0040]
As a result, the highest Al in the wear-resistant hard layer constituting the hard coating layer of the present coated tip 1-16, the present coated end mill 1-8, and the present coated drill 1-8 as the present coated cermet tool. About the composition of the content point and the Al minimum content point, and the wear resistant hard layer of the hard coating layer of the comparative coating tip 1-16 as the comparative coated cermet tool, the comparative coated end mill 1-8, and the comparative coated drill 1-8, When the content of Ti and Al was measured along the length direction using an Auger spectroscopic analyzer, the (Ti, Al) N layer constituting the wear-resistant hard layer of the coated cermet tool of the present invention had the highest Al content point. And the Al minimum content point alternately and repeatedly exist at substantially the same composition and interval as the target value, and the Al minimum content point, It is confirmed that the content ratio distribution structure of Ti and Al continuously changing from the lowest Al content point to the highest Al content point, respectively, while constituting the wear-resistant hard layer of the comparative coated cermet tool ( In the Ti, Al) N layer, no composition change was observed along the thickness direction, but the composition was substantially the same as the target composition.
Moreover, when the cross-sectional measurement was carried out using the scanning electron microscope for the average layer thickness of the surface lubrication layer of said hard coating layer, and an abrasion-resistant hard layer, all showed the substantially same value as target layer thickness.
[0041]
【The invention's effect】
From the results shown in Tables 3 to 11, the wear-resistant hard layer of the hard coating layer is repeatedly present with Al highest content points and Al lowest content points alternately at predetermined intervals in the layer thickness direction. A book composed of a (Ti, Al) N layer having a component concentration distribution structure in which the content ratios of Ti and Al continuously change from the content point to the Al minimum content point and from the Al minimum content point to the Al maximum content point, respectively. Invented coated cermet tools can be used for cutting of work materials such as Ti-based alloys, Ni-based alloys, and non-ferrous alloy materials such as Co-based alloys and Al-based alloys. Even under heavy cutting conditions, the wear-resistant hard layer of the hard coating layer has excellent high-temperature strength. layer In the comparative coated cermet tool composed of a (Ti, Al) N layer substantially unchanged in composition along the layer thickness direction, in heavy cutting of the work material composed of the non-ferrous alloy material with high mechanical impact, It is clear that chipping occurs at the cutting edge due to insufficient high-temperature strength of the wear-resistant hard layer, and the service life is reached in a relatively short time.
As described above, the coated cermet tool of the present invention is of course under normal cutting conditions such as work materials such as non-ferrous alloy materials such as Ti-base alloys, Ni-base alloys, and Co-base alloys and Al-base alloys. Because it exhibits excellent chipping resistance even when cutting is performed under heavy cutting conditions, and exhibits excellent cutting performance over a long period of time, it has improved cutting device performance and labor saving in cutting. It can respond satisfactorily to the reduction in cost, energy saving, and cost reduction.
[Brief description of the drawings]
1A and 1B show a vapor deposition apparatus used to form a hard coating layer constituting a coated cermet tool, wherein FIG. 1A is a schematic plan view, and FIG. 1B is a schematic front view.
FIG. 2 is a schematic explanatory diagram of a normal arc ion plating apparatus.

Claims

Using a vapor deposition apparatus provided with an arc ion plating apparatus and a sputtering apparatus, and provided with a rotating table for mounting a cermet substrate made of either a tungsten carbide base cemented carbide and a titanium carbonitride-based cermet in the center of the apparatus,
(A) A cathode electrode (evaporation source) of the arc ion plating apparatus is disposed opposite to each other across the rotary table, and a Ti—Al alloy for forming the highest Al content point as a cathode electrode (evaporation source) on one side A Ti-Al alloy for forming the lowest Al content point is disposed as the cathode electrode (evaporation source) on the other side, and along the outer peripheral portion of the table at a position radially away from the central axis on the rotary table. A plurality of the cermet substrates are mounted in a ring shape, and in this state, the rotary table is rotated with the atmosphere in the vapor deposition apparatus being a nitrogen atmosphere, and the cathode electrodes (evaporation sources) on both sides are rotated while the cermet substrate itself is rotated. and by generating arc discharge between the anode electrode, formed by deposition on the surface of the cermet substrate has an average layer thickness of 1~15μm
Along the layer thickness direction, the Al highest content point and the Al lowest content point are alternately present at predetermined intervals, and the Al highest content point to the Al lowest content point, the Al lowest content point to the Al It has a component concentration distribution structure in which the content ratios of Ti and Al continuously change to the highest content point,
Furthermore, the Al highest content point, composition _{_{_{formula: (Ti 1- X Al X)}}} N ( provided that an atomic ratio, X is shows a 0.40-.65),
The Al minimum content point is a composition formula: (Ti _1- _Y Al _Y ) N (however, Y is 0.05 to 0.35 in atomic ratio),
A wear-resistant hard layer comprising a composite nitride layer of Ti and Al, wherein the distance between the Al highest content point and the Al lowest content point adjacent to each other is 0.01 to 0.1 μm,
(B) The rotating table is rotated with the atmosphere inside the vapor deposition apparatus as an Ar gas atmosphere, and the cermet substrate itself mounted in the same ring shape on the rotating table is also rotated and arranged to face the rotating table. Sputtering is performed between a carbon source that is a cathode electrode (evaporation source) of a sputtering apparatus and an anode electrode, and is deposited on the wear-resistant hard layer deposited on the surface of the cermet substrate on the rotary table. A surface lubricating layer comprising an amorphous carbon layer having an average layer thickness of 0.2 to 3 μm ,
A surface-covered cermet cutting tool that exhibits excellent chipping resistance in heavy cutting by forming a hard coating layer comprising the above (a) and (b) by vapor deposition.